1. Field of the Invention
The present invention relates to a peripheral component for audio equipment, and to a speaker using the same. The present invention more specifically relates to a lightweight peripheral component for audio equipment having a good balance between a large internal loss and excellent mechanical properties, and having excellent thermal resistance and an excellent S/N ratio, and to a speaker using the same.
2. Description of the Related Art
In a case where a tweeter unit is installed in a speaker box of an audio system in which speaker units are each independently held in a speaker box, the tweeter unit may be installed in a box through a horn-shaped peripheral component. A particle board or a synthetic resin such as an ABS resin or a propylene resin is used as a material for the peripheral component. The particle board contains a thermosetting resin having a relatively high hardness such as an epoxy resin or a phenol resin for preventing deformation or strength reduction due to moisture absorption. Thus, an internal loss decreases, and vibration from a tweeter is often transmitted as it is and emitted as unnecessary noise. The synthetic resin such as an ABS resin or a polypropylene resin provides a moderate internal loss and excellent vibration control property, but often has insufficient thermal resistance or strength. In order to improve thermal resistance and strength, an inorganic-based filler such as glass fiber, titanium oxide, talc, or mica is added. However, the addition leads to weight increase and reduction of internal loss, and often results in emission of unnecessary noise.
In order to solve the above-mentioned problems, there has been proposed a speaker frame prepared by alloying a polyphenylene ether resin and a polyamide resin and adding mica to the alloy (see JP 3409579 B, for example). The polyphenylene ether resin and the polyamide resin have poor compatibility with each other and require use of a compatibilizing agent in combination. However, increase in use amount of the compatibilizing agent causes significant strength reduction due to reduction in thermal stability, decomposition, or the like. Further, alloyed polyphenylene ether resin and polyamide resin may have poor fluidity and insufficient forming property.
There has been proposed addition of a rubber-like substance or an inorganic filler to an amorphous mixture of a polyphenylene ether resin and a styrene resin, or to an alloy of a graft polymer of a polyphenylene ether resin and a styrene resin, and a polyamide resin (see JP 3317052 B, for example). Addition of a rubber-like substance improves the internal loss but causes a problem of reducing strength, and addition of an inorganic filler improves the strength but causes problems of increasing weight, reducing internal loss, and degrading an S/N ratio.